18285820 has 72 divisors (see below), whose sum is σ = 45734976. Its totient is φ = 6120576.

The previous prime is 18285791. The next prime is 18285823. The reversal of 18285820 is 2858281.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18285823) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 45862 + ... + 46258.

It is an arithmetic number, because the mean of its divisors is an integer number (635208).

Almost surely, 2^18285820 is an apocalyptic number.

18285820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18285820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22867488).

18285820 is an abundant number, since it is smaller than the sum of its proper divisors (27449156).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18285820 is a wasteful number, since it uses less digits than its factorization.

18285820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 467 (or 458 counting only the distinct ones).

The product of its (nonzero) digits is 10240, while the sum is 34.

The square root of 18285820 is about 4276.1922314134. The cubic root of 18285820 is about 263.4540100992.

It can be divided in two parts, 182858 and 20, that multiplied together give a triangular number (3657160 = T₂₇₀₄).

The spelling of 18285820 in words is "eighteen million, two hundred eighty-five thousand, eight hundred twenty".